The present invention relates to vehicle steering apparatus and process for steering a vehicle with an actuator in response to a driver's steering input.
In a steer-by-wire steering system, a steering gear mechanism for varying a steer angle of steerable wheels of a vehicle is separated from a steering wheel operated by a driver. An angle sensor senses a steering wheel angle with an encoder, and a controller varies the wheel steer angle with an actuator in accordance with the sensed steering wheel angle.
A steering system of such a type of earlier technology is composed of two or more subsystems each including a steering shaft motor for actuating a steering gear mechanism such as a rack and pinion steering mechanism, and a steering controller for controlling the steering shaft motor in accordance with an angular displacement of a steering shaft sensed by an angle sensor, and a desired target steering angle.